Form and Function of Tandem Duplicate Small RNA Molecules in Shigella dysenteriae

描述（由申请人提供）：志贺氏菌病是一种由志贺氏菌属细菌感染引起的几种常见疾病，在世界各地仍然流行。志贺氏菌病的全球负担部分是由于缺乏预防感染的疫苗， 普遍安全和可用的抗生素方案来治疗感染。虽然使用小RNA分子（sRNA）作为基于RNA的抗志贺氏菌疗法的模型或靶点的潜力是有希望的，但缺乏的是对sRNA在控制志贺氏菌生理学和发病机制中所起作用的全面理解。实现开发基于RNA的抗生素治疗志贺氏菌病的长期目标的必要的第一步是揭示sRNA控制志贺氏菌属物种的生理学和毒力的全部程度。为此，本研究的总体目标是阐明新鉴定的重复sRNA RyfA 1和RyfA 2在控制S.紫菀正在测试的中心假设是RyfA 1和RyfA 2在独特的环境条件下差异产生，并调节S。通过调控不同重叠基因组的表达来增强炭疽菌的毒力。这一假设将通过实现以下具体目标进行检验：1）确定调节RyfA 1和RyfA 2产生的铁和温度响应因子; 2）通过确定RyfA 1和RyfA 2各自的调节靶点阐明RyfA 1和RyfA 2的功能; 3）确定RyfA 1和RyfA 2单独和组合对S.炭疽菌毒力重复sRNA，RyfA 1和RyfA 2的拟议的系统表征，将有助于回答在志贺氏菌发病机制和细菌sRNA领域的基本问题，将有助于实现开发治疗志贺氏菌病的长期目标的贡献。这项研究提出了一个创新的假设，即两个具有95%序列同一性和相同预测结构的sRNA分子具有非冗余功能。这一假设将使用标准的，学生友好的，细菌遗传学和创新的高科技测定的平衡方法进行测试。学生参与拟议研究的每一步形成了创新培训计划的基础，该计划将为学生提供细菌发病机制和基于RNA的调控领域的实践经验。由此产生的技能和经验的结合将使学生能够很好地为病原菌，细菌和真核系统中核糖调节的快速发展领域做出贡献。

DESCRIPTION (provided by applicant): Shigellosis, a several diarrheal disease caused by infection with bacteria of the genus Shigella, remains endemic throughout the world. The global burden of shigellosis is due in part to the lack of a vaccine to prevent the infection and the lack of a universally safe and available antibiotic regimen to treat the infection. While the potential f using small RNA molecules (sRNAs) as models for, or targets of, RNA-based anti-Shigella therapeutics is promising, what is lacking is a comprehensive understanding of the role that sRNAs play in controlling Shigella physiology and pathogenesis. A necessary first step towards achieving the long-term goal of developing RNA-based antibiotics to treat shigellosis is to reveal the full extent to which sRNAs control the physiology and virulence of Shigella species. To this end, the overall objective of this study is to elucidate the role of newly identified duplicate sRNAs RyfA1 and RyfA2 in controlling the physiology and pathogenesis of S. dysenteriae. The central hypothesis being tested is that RyfA1 and RyfA2 are differentially produced under unique environmental conditions and modulate S. dysenteriae virulence by regulating the expression of distinct over-lapping sets of genes. This hypothesis will be tested by achieving the following specific aims: 1) identify the iron- and temperature-responsive factors regulating the production of RyfA1 and RyfA2; 2) elucidate the function of RyfA1 and RyfA2 by identifying the regulatory targets of each; and 3) determine the effect of RyfA1 and RyfA2, individually and in combination, on S. dysenteriae virulence. The proposed systematic characterization of duplicate sRNAs, RyfA1 and RyfA2, will contribute to answering fundamental questions in the fields of Shigella pathogenesis and bacterial sRNAs, contributions that will facilitate achievement of the long-term goal of developing therapeutics to treat shigellosis. The proposed study puts forth the innovative hypothesis that two sRNA molecules that share 95% sequence identity and a identical predicted structure have non-redundant functions. This hypothesis will be tested using a balanced approach of standard, student friendly, bacterial genetics and innovative high-tech assays. Student involvement in every step of the proposed study form the foundation of an innovative training program that will provide students with practical experience in the fields of bacterial pathogenesis and RNA-based regulation. The resulting combination of skills and experience will position students well to contribute to the rapidly advancing fields of ribo-regulation in pathogenic bacteria, commensal bacteria and eukaryotic systems.